Oct. 30-Nov. 2:Build, which draws developers from around the world. The sold-out event will be at Microsoft's Redmond campus. (The conference will be streamed live and video will be posted to Microsoft's Channel 9 website within 24 hours.)

Nov. 9-11:Wowzapp, a hackathon to create Windows apps. It takes place in more than 30 locations around the world.

Microsoft is known for its vast network of developers — independent, third-party creators of applications and programs that run on its Windows platform.

But can Microsoft persuade that extensive developer base to create apps for Windows 8, an operating system that's radically different from any other Windows version and comes with uncertainty over whether customers will flock to it?

As Microsoft prepares to launch Windows 8 at a media event Thursday in New York, getting developers to create apps for the operating system is one of the biggest questions hovering over the company. It's particularly crucial to the success of Windows RT, the Windows 8 version designed to run on ARM-based tablets competing directly with Apple's iPad.

Unlike Windows 8 machines, devices running Windows RT will not be able to run legacy or desktop Windows apps (other than the Office suite that comes with the devices). Rather, customers will have to rely on apps available only through the online Windows Store.

"Without stellar apps, Windows RT is a machine that runs Office and a Web browser," said Wes Miller, an analyst with independent research firm Directions on Microsoft in Kirkland. But "if developers build the apps, that's what drives the platform."

The challenge for Microsoft is that many developers seem to be in wait-and-see mode.

Microsoft, meanwhile, has been pushing its new platform hard, significantly increasing the number of "dev camps," localized gatherings for developers to learn about creating Windows apps. It also is sponsoring a worldwide hackathon to create apps, and next week it welcomes developers to the Redmond campus for Build, the company's annual conference for third-party developers

Company executives have also touted the potential economic opportunity tied to Windows 8, saying, as CEO Steve Ballmer did, that 400 million PCs will be running Windows 8 within the next year.

"Microsoft has a huge install base. As a developer, you can't ignore that," said Frank Gillett, an analyst with Forrester Research. "The question is how fast the install base will convert [to Windows 8] and how fast [developers can] monetize that."

Windows Store

The Windows Store is Microsoft's answer to the app marketplaces that have cropped up in recent years, most notably the Apple iTunes App Store and Google Play.

"The big question mark heading into the launch is: Are the apps going to be there?" said Tom Mainelli, an analyst with research firm IDC. "There's not a lot in there right now."

Early this week, the Windows Store had more than 7,000 apps globally and 5,000 in the U.S., according to WinAppUpdate, a website that's an independent project of Directions on Microsoft's Miller.

The number has been increasing rapidly but it's not near the 250,000 iPad apps available.

Still, comparing numbers of apps is like comparing "horsepower on a car," Miller said. "The typical consumer doesn't really care. More important is: Does it get done what I want to get done?"

"Starting line"

Tim O'Brien, Microsoft's general manager for developer and platform evangelism, said "the launch of Windows 8 is really the starting line for the building out of the ecosystem. It's not the endpoint people should use to build some numbers-based judgment of how it's doing. It's the starting line."

What seems to be motivating most of the developers who are creating Windows 8 apps, O'Brien said, is the "economic opportunity through the reach of the number of PCs to be shipped."

By the end of 2012, he said, Windows 8 apps will be available in 230 markets around the world.

"The global nature of the business opportunity is really the primary incentive," he said.

Unproven

Developers, for the most part, want Windows 8 to succeed because it benefits them to have another platform to create for, said Mainelli of IDC. "At the same time, they're hesitant to spend money and resources developing apps for a platform that hasn't proven itself yet," he added.

That was borne out in a recent report from IDC and mobile-platform company Appcelerator in which 33 percent of the mobile-app developers surveyed said they were "very interested" in developing for Windows 8 tablets, compared with 83 percent for the iPad and 66 percent for Android tablets.

Those surveyed were enthusiastic about Microsoft's efforts to make it easier for developers to write apps that will run on both Windows 8 desktops and tablets. But the report also noted "Microsoft has a lot of work to do to convince developers that Windows 8 will be a successful platform."

Also a new factor is the Windows Store. It has an economic model that differs from what Windows developers may be used to, when they sold their apps (usually higher-priced, complex and powerful) directly on their own websites. They kept all the proceeds or took in revenue through third-party distributors.

With the Windows Store, the focus shifts to smaller, lower-priced apps, said Gillett, the Forrester analyst. And Microsoft now acts as distributor, getting an industry-standard 30 percent for the first $25,000 of an app's sales, 20 percent after that.

Holding off

One developer holding off on a Windows 8 app is Len Kawell, chief technology officer and co-founder of Kirkland's Pepper Networks. The company just launched Timebox, a personal-history app, on Apple iOS.

Kawell, who previously worked at Microsoft, said he's excited about Windows 8 and "probably this time next year, it will be obvious that we need to be there."

But it will take time for Windows 8's customer base to grow. As a small startup, "we need to go where the customers have devices today," Kawell said.

Early adopter

Meanwhile, Seattle-based Allrecipes.com has decided to be an early app provider.

The company, which is launching two apps on Windows 8, had three questions when evaluating whether to jump aboard the platform: how its content would look, whether Windows 8 would provide enough scale and whether it was the right platform for Allrecipes' advertising-driven model, said Bill Reller, Allrecipes.com's vice president of new business.

It decided the content would look good and that Windows 8's live tiles — square and rectangular tiles on the device screen — would be an interesting way to showcase Allrecipes' seasonal content.

And it believes the customer base will grow, luring more advertisers.

"We have tremendous confidence in Microsoft's ability to employ the platform," Reller said.